In the training of military, commercial and other personnel, it is often desirable to make use of a target tracking simulator in which the trainee must attempt to keep a given target within the sights of the tracking apparatus. In other applications the trainee must detect and recognize realistic targets against a realistic background of excellent real world-like fidelity provided by a medium such as a color transparency. In such a target tracking simulator or target recognition trainer, a movable background is provided and a movable target can be introduced into the scene by the operator of the simulation apparatus, whether the simulator be under human or automatic control. In the past, television screens have been used to provide the background image, and the target has been introduced electronically into the scene by "blanking out" a portion of the video background scene and inserting an image of the target upon the video background at a desired position, attitude and apparent distance. One such technique is described in U.S. Pat. No. 3,746,782 issued to Carl R. Driskell.
Because of the nature of television image generation, the resolution of video background images is not of the highest quality. The present invention makes use of a high resolution film strip to generate the background image, uses video techniques to generate the target image, and then inserts the optical target image into the background at the desired position and aspect by a novel technique. Specifically, a cathode ray tube is used to illuminate the background film image, and a video camera is used to observe the target and generate an electronic video signal which "blanks out" the CRT background illumination at the desired target position for the exact size of the target image. The target image is then optically inserted at this "blanked out" space for observation by the simulator trainee. In this manner, the high resolution of film background and foreground terrain are retained in the target tracking simulator.
In a further improvement of the present invention, the target image, or portions thereof, can be blanked out or occulted by a display of "foreground" images, and in this manner the target appears to the trainee observer to weave in and out of the background and foreground in a most realistic manner.